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Original Message
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| RE: any ideas on a 1/4mile time or hp guess on this CJ |
| By Derek - 03/12/2002 1:55:43 AM; IP 207.102.191.65 |
Mike, you've received some pretty good input here so far. Don't buy into the 'factory sales literature', or the often quoted Hot Rod magazine test on the original '68 CJ Mustangs, that saw it run 13.56@108...that was NOT the kind of car you could buy off the showroom floor!!
My personal experience, with a similar '69 Cobra Fairlane to what one of the other respondents had (SCJ/C-6/3.50 open/stock exhaust), was that it hit a best ever 13.92 @ 102.34
In your case, you've got a little lighter car, a little better intake (Ford only credited it with 6-8 hp over the cast iron one), but the cam is really marginal, and the exhausts are too restrictive. Sorry, but that is just a cheaper 'generic' single-pattern cam that's not optimized for the FE cylinder heads or induction/exhaust setups.
If you check the Crane or Lunati catalogues, you will find that their 'factory replacement' cam for a 390GT/428CJ has about 228I/234E duration @ .050" lifter rise, and .481"/.490" lift. The one you have gives up the benefit of the added exhaust duration, in favor of some more lift. Unfortunately, the net effect is very little change in the power output overall.
Assuming you've still got the 735cfm Holley on top of that 'H' manifold, that's good enough to run 9 second quarters on a Super Stocker, so it should be good for almost anything you'd want to do with it. Jetting will run around 70-72 front and 85-86 rear. This manifold does not have the equalized fuel distribution of the 'Sidewinder' 427 manifold, so you might have to bias the jetting to the low side of the dual-plane design.
You ARE going to need more cam timing, and I'd suggest looking at some of Crower's listings. I can't remember the grind number, but they have a cam around 237I/247E duration @ .050", with around .550"/.580" lift. Upgrade your valve springs to something in the 320-340 lbs. range
They advertise this cam as having "..violent mid-range acceleration and torque", which is what you want. This will probably add in the neighbourhood of 50+hp to your motor. It will kill off a little torque at the engine speeds you likely leave the starting line at (which can actually be a good thing!), but will more than make up for it later, pulling hard right to 6,500rpm, which is as far as you really want to go anyway.
Get some headers on the car to get rid of all that extra airflow through the motor! The Hooker 'standard' headers with the one pipe that slips together work well, and have decent ground clearance.
You don't indicate if you're going to run with street tires or slicks, and that can impact other components. If you'd like your car to be able to get into the 12's almost like you'd drive it on the street, consider an aluminum flywheel to take out some of the stored rotational energy during the launch, in favor of allowing the engine to wind-up quicker as it gets going. With 9" slicks, the stock 35 lbs iron flywheel weight will do fine with that 2.32 1st gear and the 3.91's.
It wouldn't be unrealistic to expect 12.7-12.5 ET's, at about 104-105mph (Today's NHRA Stock Eliminator CJ Mustangs are going mid-to-high 10's at over 126mph!)
Good luck with your car. Keep it in one piece...they go up in value daily! |
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